Effector T Cells and their Functions
Cytokine IL-4 primarily stimulates:
B cells to class-switch to IgE
Effector helper T cells express ______________ and secrete __________________ to recruit/activate other WBCs to destroy microbes
CD40L, cytokines
All nucleated cells express _________ receptors, also called:
Fas, CD95
Effector CTLs express CD95L, also called ____________. This can bind to the ___________ receptor, and this interaction activates a _________________ pathway, which causes apoptosis.
FasL, Fas, caspase
Effector helper T cells secrete cytokines to: (4 answers)
activate macrophages, augment APC function, stimulate NK cell function, regulate B cell response
What are the 2 primary function of effector TH1 cells?
activate macrophages, promote cell-mediated immune response
CTL killing requires _______________ between CTL and target cell.
cell-to-cell contact
What is cell-mediated immunity described as?
cell-to-cell interactions
Differentiated effector T cells exit the secondary lymphatics enter _____________________, and go to regions of infection or injury in the __________________________ tissues, where effector functions of T cells take place.
circulation, peripheral
In M2 macrophage activation, TH2 cells stimulate macrophages to synthesize factors that promote ____________________ synthesis and ________________ in chronic parasitic diseases and allergies.
collagen, fibrosis
Each helper T cell subset secretes a different ___________________ profile to direct the immune response to the initiating antigen.
cytokine
What are the two different methods used by CTLs to induce apoptosis in target cells?
degranulation, Fas-FasL binding
What is the primary function of TH17 effector cells?
destroy extracellular bacteria/fungi by neutrophilic inflammation
Whichever helper T cell subset that develops depends on stimuli present during:
early immune response
Cell mediated immunity of the adaptive immune system is the __________________ function of T lymphocytes and serves as the defense mechanism against microbes that _______________________ within phagocytes and nonphagocytic cells.
effector, survive and replicate
Cytokine IL-5 stimulates:
eosinophil degranulation
TH17 T cell subset differentiates during activation in response to ______________________________________ and ______________ that stimulate inflammatory responses within the _______________.
extracellular bacteria, fungi, tissues
What is they type of antigen that stimulates differentiation into TH17 cells?
extracellular bacteria/fungi
Secretion of TNF by TH1 cells to promote inflammation does so by promoting the ____________________ and _____________________ of WBCs from the vasculature and through the tissue spaces.
extravasation, chemotaxis
If a pathogen is resistant to a phagocyte's intracellular killing mechanisms, ______________________ formation can occur.
granuloma
What is the type of antigen that stimulates differentiation into TH2 cells?
helminths and allergens
The TH2 cell subset differentiates during activation in response to ______________________ that stimulate _______________ and ________________ degranulation.
helminths and allergens, mast cell, eosinophil
Defects in T cells results in an increased susceptibility to ___________________. If a patient has low T cell numbers chronically, they most likely have _________________________.
infections, immunodeficiency
TH1 cells also augment __________________ by secreting _______, which stimulates increased ______________________ cell expression of cell adhesion molecules (CAMs) and production of chemokines.
inflammation, TNF, endothelial
While TGF-B works as an anti-inflammatory for M2 macrophages, in _________________ areas, it needs to be ________________________. However, if it is too much, then it could lead to issues such as IBD, Crohns, etc.
intestinal, pro-inflammatory
What is the type of antigen that stimulates differentiation into TH1 cells?
intracellular microbes
Effector cytotoxic T cells:
kill infected cells
Effector cytotoxic T cells (CTLs) recognize and _______________ host cells infected with microbes that replicate in the _______________________. CTLs can also recognize/kill ___________________.
kill, cytoplasm, tumor cells
The primary function of CTLs is to ________ cells infected with an __________________________ and also _____________ cells.
kill, intracellular microbe, tumor
IL-4 and IL-13 from effector TH2 cells stimulate ____________________ differently than how _______ stimulates them, resulting in ___________________________.
macrophages, IFN-y, alternative macrophage activation
What cells do TH1 cells activate? How do these cells recognize it is an intracellular organism?
macrophages, NK cells, dendritic cells; stimulate PRRs
What is being used therapeutically against PD-1 and PD-L1 to block the inhibition of effector T cells? This action keeps effector T cells __________ longer.
monoclonal antibodies, active
Additionally, TH1 cells participate in activation/differentiation of _______________________ into effector __________.
naive CD8 T cells, CTLs
Degranulation is the release of granular contents that consist of: (2 things)
perforin and granzymes
Cytokines IL-4 and IL-13 together stimulate ______________________ and increased _______________________ in the gut as well as ___________________________ of macrophages. This serves to flush parasites out and prevents them from burrowing into the epithelium.
peristalsis, mucus secretion, alternative activation
TH1 activation of macrophages via IFN-y and CD40L expression boost ___________________ activity, upregulate how many ______________ __________ will be produced inside cell, and start expressing both ________________________ and higher amounts of ____________.
phagocytic, killing enzymes, costimulators, MHCII
CTLs secrete __________ to promote the cell-mediated response.
IFN-y
What are the pro-inflammatory cytokines?
IL-1, IL-6, IL-23
Additionally, M2 macrophages secrete _______ and _________ which act as ___________________ cytokines that suppress M1 macrophages and TH1 responses.
IL-10, TGF-B, anti-inflammatory
TH1 cell differentiation is driven by _________ and _________ in response to ________________________________ that activate dendritic cells, natural killer cells, and macrophages
IL-12, IFN-y, intracellular microbes
Which cytokines are produced in response to TH1 initiating antigens? What secretes them?
IL-12, IFN-y; macrophages, DCs, NK cells
TH17 cells will secrete _______, _______, and ________, promoting _______________________.
IL-17, IL-21, IL-22, differentiation
To activate CTLs, TH1 cells can either secrete ________________ to augment CD8 activation, or they can augment _____________________ via _________________, which helps them become more effective at activating CD8 T cells.
IL-2 and IFN-y, professional APCs, CD40-CD40L binding
What cytokines are secreted by TH1 cells?
IL-2, INF-y, and TNF
What signature cytokines are secreted by effector TH2 cells in response to helminths and allergens?
IL-4, IL-5, and IL-13
Which cytokine drives TH2 differentiation? This cytokine is secreted by which innate immune cells?
IL-4, mast cells and eosinophils
Patients hyper-secreting __________ in response to an allergen are atopic.
IgE
The primary function of effector TH2 cells is to stimulate __________- and _____________________ -mediated reactions that eradicate helminthic infections.
IgE, eosinophil
Which cytokines are produced in response to TH2 initiating antigens? What secretes them?
Il-4; mast cells
What is the name of the inhibitory receptor (related to CTLA-4) expressed by effector T cells in the tissues that works to limit the inflammatory response?
PD-1
Binding of _____________ to PD-1 results in T-cell ________________.
PD-L1, inhibtion
Which cytokines are produced in response to TH17 initiating antigens? What secretes them?
TGF-B, pro-inflammatory cytokines; tissue cells
IL-12 and IFN-y stimulate:
TH1 cell differentiation
What are the three primary helper T cell subsets?
TH1, TH2, TH17
Perforins are ____________ proteins, and granzymes are ________________ ______.
pore forming, serine esterases
Perforins form a __________________, which creates a channel for granzymes to enter and activate an ___________________________ pathway.
pore, apoptotic caspase
TH17 cell differentiation is driven by ____________________ (such as IL-6) and _________________ in mucosal areas.
pro-inflammatory cytokines, TGF-B
What does IL-22 do?
promotes epithelial integrity, stimulates production of antimicrobial peptides/mucins
What does IL-17 do?
recruits neutrophils and produces defensins
What 2 factors make TH1 cells augment the APC and phagocytic functions of macrophages?
secreting IFN-y, binding of CD40L to CD40
When do mature, naive CD4+ T cells differentiate into one of the three subsets?
upon activation
